Small electronic devices are commonly powered by batteries, which allow such devices to be portable. However, as battery use continues, the battery voltage drops, sometimes uniformly and sometimes in spurts, depending in part on the type of battery, the type of electronic device, and the frequency of device use. Such variations in the battery voltage may have undesirable effects on the operation of the electronic device powered by the battery. Consequently, DC-DC converters are commonly used to provide a constant and stable output supply voltage from the battery to the electronic device.
Switched capacitor circuitry is used in several power converter applications and is particularly advantageous where the use of inductors is to be avoided. The circuitry may include voltage regulation for controlling the magnitude of the output voltage notwithstanding changes in magnitude of the input voltage and changes in the load driven by the circuitry. A conventional method to regulate voltages in fixed gain capacitor DC-DC converters is to use pulse frequency modulation (PFM) or pulse skipping.